The uptake and translocation of fluridone {1-methyl-3-phenyl-5-[3-(trifluoromethyl)phenyl]-4(1H)-pyridinone} were examined in sago pondweed (Potamogeton pectinatus L.) and Richardson pondweed [Potamogeton richardsonii (Ar. Benn.) Rydb.]. Root and shoot tissues of both species were isolated from each other with wax barriers and treated individually with 1.0 ppm 14C-fluridone. Both tissues bioconcentrated fluridone, but the amount absorbed represented 1% or less of the total herbicide available. Limited root-to-shoot translocation occurred, but shoot-to-root transport was negligible. In contrast to fluridone, highly mobile glyphosate [N-(phosphonomethyl) glycine] translocated from the shoots to the roots in sago pondweed. No metabolism of fluridone was detected in sago pondweed.
